Carbon Nano Tube-Polymer Hybrid Nanocomposite Electrodes for Porous Polydimethylsiloxane Sponge-Based Flexible Triboelectric Nanogenerators

2021 ◽  
Vol 21 (9) ◽  
pp. 4680-4684
Author(s):  
Dae-Hyeon Kwon ◽  
Jaebum Jeong ◽  
Yongju Lee ◽  
Jun-Kyu Park ◽  
Suwoong Lee ◽  
...  

Flexible triboelectric nanogenerators (TENGs) have attracted much attention because of its environmentally friendly, practical, and cost-producing advantages. In flexible TENGs, it is important to study the flexible electrodes in order to fabricate the fully flexible devices. Here, we compared electrical characteristics of the sponge porous polydimethylsiloxane (PDMS)-based flexible TENGs with two types of flexible electrodes, copper and carbon nanotube (CNT)-PDMS electrodes. The output voltage and maximum power density of sponge PDMS-based flexible TENGs with copper and CNTPDMS electrodes were compared. The voltage and power density of sponge PDMS-based flexible TENGs with CNT-PDMS electrodes were improved compare to those with copper electrodes. The output voltage and the maximum power density of sponge PDMS-based flexible TENGs with copper and CNT-PDMS electrodes increased 4 times and 7 times, respectively. It is attributed to higher electrical conductivity and stably flow electricity of CNT than those of copper.

2020 ◽  
Vol 8 (16) ◽  
pp. 7880-7888 ◽  
Author(s):  
Leilei Zhao ◽  
Liqiang Liu ◽  
Xiya Yang ◽  
Hongxin Hong ◽  
Qianming Yang ◽  
...  

A maximum power density of 1.838 W m−2 is achieved and 30 LEDs can be lighted up by the cumulative water droplets driven freestanding triboelectric nanogenerator demonstrating the great potential for hydrodynamic energy harvesting from rain.


2012 ◽  
Vol 724 ◽  
pp. 389-392 ◽  
Author(s):  
Yuta Ibusuki ◽  
Yoshihiro Hirata ◽  
Soichiro Sameshima ◽  
Naoki Matsunaga

Cell performance was measured for four types of Ni (40 vol%)-Gd-doped ceria (GDC) anode-supported solid oxide fuel cells with GDC electrolyte (40-120 μm thickness) of Ce1-xGdxO2-x/2 compositions (x = 0.05, 0.1, 0.15 and 0.2) at 773-1073 K using a H2 fuel. (La0.8Sr0.2)(Co0.8Fe0.2)O3 cathode was printed on the GDC films. The open circuit voltage and maximum power density at 873-1073 K showed a maximum at x = 0.1. The maximum power density at x = 0.1 was 166 and 506 mW/cm2 at 873 and 1073 K, respectively. The excess oxygen vacancy at x = 0.1-0.2, which does not contribute to the oxide ion conductivity, reacts with a H2 fuel to form electrons (H2 + VO 2H+ + VO×, VO× VO + 2e-). This reaction reduces the cell performance.


Author(s):  
L Chen ◽  
J Zheng ◽  
F Sun ◽  
C Wu

The power density is taken as an objective for performance analysis of an irreversible closed Brayton cycle coupled to variable-temperature heat reservoirs. The analytical formulas about the relationship between power density and working fluid temperature ratio (pressure ratio) are derived with the heat resistance losses in the hot- and cold-side heat exchangers, the irreversible compression and expansion losses in the compressor and turbine, and the effect of the finite thermal capacity rate of the heat reservoirs. The obtained results are compared with those results obtained by using the maximum power criterion. The influences of some design parameters, including the temperature ratio of the heat reservoirs, the effectivenesses of the heat exchangers between the working fluid and the heat reservoirs, and the efficiencies of the compressor and the turbine, on the maximum power density are provided by numerical examples, and the advantages and disadvantages of maximum power density design are analysed. The power plant design with maximum power density leads to a higher efficiency and smaller size. When the heat transfers between the working fluid and the heat reservoirs are carried out ideally and the thermal capacity rates of the heat reservoirs are infinite, the results of this article become similar to those obtained in the recent literature.


2001 ◽  
Vol 08 (04) ◽  
pp. 377-391 ◽  
Author(s):  
Lingen Chen ◽  
Junlin Zheng ◽  
Fengrui Sun ◽  
Chih Wu

In this paper, the power density, defined as the ratio of power output to the maximum specific volume in the cycle, is set as the objective for performance analysis of an irreversible, regenerated and closed Brayton cycle coupled to constant-temperature heat reservoirs from the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM). The analytical formulae about the relations between power density and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers and the regenerator, the irreversible compression and expansion losses in the compressor and turbine, and the pressure loss in the pipe. The results obtained are compared with those obtained by using the maximum power criterion. The influences of some design parameters, including the effectiveness of the regenerator, the temperature ratio of heat reservoirs, the effectivenesses of heat exchangers between working fluid and heat reservoirs, the efficiencies of the compressor and the turbine, and the pressure recovery coefficient, on the maximum power density are illustrated by numerical examples, and advantages and disadvantages of maximum power density design are analyzed. When heat transfers between working fluid and heat reservoirs are carried out ideally, the results of this paper coincide with those obtained in recent literature.


2018 ◽  
Vol 8 (12) ◽  
pp. 2504
Author(s):  
Junxian Shi ◽  
Anhuai Lu ◽  
Haibin Chu ◽  
Hongyu Wu ◽  
Hongrui Ding

Developing simple and cheap electrocatalysts or photocatalysts for cathodes to increase the oxygen reduction process is a key factor for better utilization of microbial fuel cells (MFCs). Here, we report the investigation of natural wolframite employed as a low-cost cathode photocatalyst to improve the performance of MFCs. The semiconducting wolframite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The band gap and photo respond activities were determined by UV-vis spectroscopy and linear sweep voltammetry (LSV), respectively. Compared with the normal graphite cathode, when MFCs were equipped with a wolframite-coated cathode, the maximum power density was increased from 41.47 mW·m−2 to 95.51 mW·m−2. Notably, the maximum power density further improved to 135.57 mW·m−2 under light irradiation, which was 2.4 times higher than with a graphite cathode. Our research demonstrated that natural wolframite, a low-cost and abundant natural semiconducting mineral, showed promise as an effective photocathode catalyst which has great potential applications related to utilizing natural minerals in MFCs and for environmental remediation by MFCs in the future.


2019 ◽  
Vol 37 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Aleksandr Klimov ◽  
Ilya Bakeev ◽  
Efim Oks ◽  
Aleksey Zenin

AbstractWe describe here the design, main parameters, and characteristics of a forevacuum-pressure plasma-cathode electron source based on a hollow-cathode discharge. The source generates a continuous focused electron beam with energy up to 30 keV and current up to 300 mA at a pressure of 10–50 Pa. The focused electron beam reaches a maximum power density of 106 W/cm2. The source utility has been demonstrated by its application for processing and cutting of ceramic.


2009 ◽  
Vol 615-617 ◽  
pp. 885-888 ◽  
Author(s):  
Simon Barker ◽  
Rupert C. Stevens ◽  
Konstantin Vassilevski ◽  
Irina P. Nikitina ◽  
Nicolas G. Wright ◽  
...  

The development of silicon carbide technologies has allowed for the development of sensors and electronics to measure the changes in a variety of hostile environments. A problem has been identified with reliable and efficient ways to power such sensors in these hostile environments. It is likely to be impractical to run power cables to these sensors and battery power has a finite lifetime. Recent research has demonstrated many energy scavenging techniques but to date none have been developed with a view of operation in hostile environments. To investigate the power density achievable from a SiC based energy scavenging device a SiC pin diode was exposed to both broad spectrum light form a tungsten halogen bulb and a 255 nm UV source. IV and CV measurements were used to determine the structural properties and photovoltaic response of the device, dark saturation current, induced photo current and the fill factor. We present the characteristics and maximum power density of these devices at temperatures between 300 K and 600 K. We demonstrate that the maximum power density achievable decreases with temperature. This is mostly due to the reduction in the built in potential from the pn junction, and the reduction of the generated photocurrent.


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